After seeing some cool consolized gamegear projects I decided to tackle a consolized gameboy advance. I used the gba tv converter for this project:
This converter is the most common tv adapter for the gba (it's also very cheap). And the best news is bacteria was nice enough to post the soldering pinout to bypass the ribbon cable which tends to lose connectivity very easily:
This device uses a sony cxa2075 video encoder, nice. The device plugs itself into the gba power connections so you can power both the gba and tv converter from a single power supply which is also nice.
When I got my tv converter running I was presented with a s-video picture completely full of jailbars. After much pain and suffering I discovered that disconnecting the capacitor on the chroma output didn't disable chroma in s-video. To disable chroma I had to disconnect the caps for both chroma and composite video, which made me consider that they wired composite video and s-video together in the av cable. I snipped off the built in av cable and wired up my own s-video jack and sure enough the jailbars suddenly were 90% removed. To fix the other 10% of the jailbars I just weakened the chroma line until they completely went away since these jailbars are only on chroma. I also adjusted the luma output resistor to a better value. The s-video circuit in this was wired up like the application circuit from the datasheet which certainly isn't ideal so a little circuit mucking fixed all distortion. There was a lot of jailbar distortion at first it's like night and day compared to before. Here's the first build of it that's working as it should:
I need to buy a parts gameboy to harvest a cartridge slot so I can remotely wire the slot.
Consolized gba + home built devcart + marioland colorized romhack ftw!
http://www.youtube.com/watch?v=JjcG0jn2Jr8&feature=youtu.be
This converter is the most common tv adapter for the gba (it's also very cheap). And the best news is bacteria was nice enough to post the soldering pinout to bypass the ribbon cable which tends to lose connectivity very easily:
This device uses a sony cxa2075 video encoder, nice. The device plugs itself into the gba power connections so you can power both the gba and tv converter from a single power supply which is also nice.
When I got my tv converter running I was presented with a s-video picture completely full of jailbars. After much pain and suffering I discovered that disconnecting the capacitor on the chroma output didn't disable chroma in s-video. To disable chroma I had to disconnect the caps for both chroma and composite video, which made me consider that they wired composite video and s-video together in the av cable. I snipped off the built in av cable and wired up my own s-video jack and sure enough the jailbars suddenly were 90% removed. To fix the other 10% of the jailbars I just weakened the chroma line until they completely went away since these jailbars are only on chroma. I also adjusted the luma output resistor to a better value. The s-video circuit in this was wired up like the application circuit from the datasheet which certainly isn't ideal so a little circuit mucking fixed all distortion. There was a lot of jailbar distortion at first it's like night and day compared to before. Here's the first build of it that's working as it should:
I need to buy a parts gameboy to harvest a cartridge slot so I can remotely wire the slot.
Consolized gba + home built devcart + marioland colorized romhack ftw!
http://www.youtube.com/watch?v=JjcG0jn2Jr8&feature=youtu.be